1. Field of the Invention
This invention relates to the preparat1on of capsules containing edible ingredients, that usually comprise telescopically engaged capsules halves, and more particularly to a method for sealing such capsules to render them tamper-proof and tamper-evident.
2. Description of the Prior Art
The capsules to which the present method relates are well known and have been in broad use for many years. Such capsules are generally prepared from an edible natural substance such as gelatin, and are telescopically engageable tubes, each tube having one end thereof sealed, so that upon co-axial disposition, they are capable of holding a quantity of material. Generally, such capsules are utilized in the pharmaceutical and food industries, to hold edible and pharmaceutically active materials such as medicines, vitamin preparations, and other edibles both solid and liquid. Generally, the materials from which the capsules are prepared are hydrophilic, and thereby adapted to dissolve in the intestine after ingestion.
One of the difficulties that has long been encountered in the use of such capsules as stated, has been their ability and occasional tendency to disengage from each other, whereby the contents of the capsule escape and are lost. Accordingly, the prior art is replete with numerous approaches directed to the maintenance of the sealing engagement between the capsule halves.
The problem of the disengagement of the capsule halves from each other has recently become more acute, in view of the well publicized deliberate disassembly of certain encapsuled medicaments and the inclusion therein of certain poisons such as cyanide. This deliberate act was successfully accomplished because the capsules were inadequately sealed and gave no evidence of their tampering. That is, the slip fit engagement between the capsule halves is easily disrupted and the cap part of the capsule removed, so that an intruder may insert a small but lethal quantity of poison or other disruptive agent therein.
The events described above have spurred a renewed interest on the part of the industry and the public at large to develop methods and associated apparatus to render these capsules tamper-proof by the placement of appropriate indicators of tampering on the capsule. One such approach to this problem is disclosed in U.S. Pat. No. 1,861,047, wherein a circular band of hardened gelatin is disposed about the seam that occurs between the respective capsule halves, comprising the body and the cap part that receives it. The application of the hardened gelatin band is presumed to indicate when the capsule parts have been separated and to thereby offer an indication that tampering has occurred.
The procedure outlined in the '047 patent and the capsules treated thereby have been found to be deficient, in that it is possible to separate the body part from the cap part, modify the contents thereof and thereafter replace the cap and body parts in position against each other and reband the rejoined capsule so as to avoid detection of tampering.
Further, while it is desirable to render the capsules tamper-proof, i.e. resistant or better yet, incapable of disassembly, it is equally desirable to render such capsules tamper-evident, i.e. capable of disassembly, adulteration and reassembly, however, offering visual indication of the same. The need for a tamper-evident seal is far greater, as it is extremely difficult to assure that each capsule will be properly sealed so as to be tamper proof.